Watering Calculator
Enter area, plant type, climate, and sun to estimate weekly inches and gallons.
Water deeply and infrequently to grow deep roots. Early-morning irrigation reduces disease. Container and sandy soils need more; clay and shade need less.
What the inputs mean
Enter the area you are actually watering, not the area of the whole garden — bare soil between rows does not transpire. Plant type and climate set the demand, and sun exposure adjusts it; the tool then multiplies depth by area and converts cubic feet of water into gallons so you can translate the answer into watering-can or hose minutes.
How to act on the answer
Use the gallons figure to calibrate your watering in one sitting rather than guessing every day. Water to the depth the tool indicates, then wait and check soil moisture two to three inches down before watering again — the tool gives you a weekly total, and how you split it across the week matters less than reaching that total and letting the surface dry between cycles.
What this tool cannot know
It is an estimate driven by typical demand rather than a measurement of your soil. Sandy soil holds far less water than clay and needs smaller, more frequent applications, mulch reduces evaporation substantially, and a drip system delivers water far more efficiently than overhead watering. Treat the number as a starting point and adjust from what the soil is doing.
Where it fits in the season
A calculator is only as good as the location data behind it, so two other pages usually belong in the same session. The ZIP lookup establishes your zone and typical frost dates, which is the baseline that watering calculator is reasoning from, and the monthly zone checklists turn the same baseline into an ordered set of jobs for the current month. If you are working from a specific planting plan rather than a blank bed, the garden plan templates carry published spacing and crop lists you can feed straight into the planner.
Everything on this page runs in your browser from data shipped with the site. There is no account, nothing is uploaded, and the numbers you type are not stored on a server — which also means a printed sheet or a screenshot is the only copy you will have if you close the page. See all garden tools →
Related guides
Watering guide · Fertilizing guide · Composting guide · Raised bed guide · all topic guides →